-LRB- CNN -RRB- -- The Central Americans crossing the U.S. border in massive waves have been described as immigrants or refugees .

The distinction is significant and could determine whether the migrants are subject to deportation to their home country or eligible to remain in the United States under asylum .

What is an immigrant ?

An immigrant is someone who chooses to resettle to another country .

The United States has a legal process for that immigrant to seek legal residency and eventually citizenship .

Many immigrants , however , do n't have such legal status and are thus undocumented . As such , they are subject to `` removal '' or deportation from the United States .

There are 11 million undocumented immigrants in the United States -- a problem that has led Democrats and Republicans alike to declare the U.S. immigration system as `` broken . '' Congress has been deadlocked for years on how to reform immigration laws .

`` Migrants , especially economic migrants , choose to move in order to improve the future prospects of themselves and their families , '' the U.N. High Commissioner for Refugees says . `` Refugees have to move if they are to save their lives or preserve their freedom . ''

What is a refugee ?

A refugee is someone who has been forced to flee his or her home country .

As such , refugees can apply for asylum in the United States , a process that could take years .

Getting refugee status is n't easy .

The applicants have to prove that if they return to their home country , they 'll be injured because of their race , religion , nationality , membership in a particular social group or their political opinion .

`` Refugees are generally people outside of their country who are unable or unwilling to return home because they fear serious harm , '' the U.S. Citizenship and Immigration Services says .

The Central Americans overwhelming the U.S.-Mexican border are Hondurans , Guatemalans and Salvadorans . Many are fleeing drug - and gang-fueled violence back home .

Is the violence -- any kind -- grounds for a refugee claim ? Not necessarily .

The violence has to be targeted to a person specifically , and that 's where things get complicated . Every case is different , and because of a law signed by President George W. Bush in 2008 , children fall into a special class .

The William Wilberforce Trafficking Victims Protection Action Act , named after a 19th century British abolitionist , is designed to crack down on the global child slave trade . The U.S. law ensured that children who came to the country got a full immigration hearing instead of being turned away or sent back . The hearing would determine whether the children had a valid claim for asylum .

The law is now cited as one cause behind a projected 90,000 children from Central America and Mexico who will cross the U.S. border alone or with other children this year , a huge increase over the 39,000 that the Border Patrol detained last year .

Asylum is a protection available to people who are already in the United States or are seeking admission at the U.S. border .

CNN 's Tom Cohen contributed to this report .

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The distinction can determine deportation from U.S. or the chance to stay under asylum

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An immigrant chooses to resettle to another country

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A refugee is forced to flee his or her home country

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Getting asylum in the United States is n't easy and could take years